Method and device for distributing mail items

ABSTRACT

The invention relates to the distribution of mail items with information on the surface of the mail items. Distribution occurs successively by means of various sorting machines. Sorting in particular is carried out in a succession of operations for the last point of distribution. According to the invention, distribution points are determined once the mail items have been received in the first sorting machine and the thicknesses of the mail items are measured by optical scanning of the mail item surfaces. Mail item thicknesses allocated to the distribution points are registered, stored and statistically prepared if required. Optimized sort programs are then calculated for sorting machines assigned to the various distribution points based on information regarding thickness, and the mail items are distributed accordingly. The optimized sort programs and data on determined thickness alone can be transmitted to the sorting machines assigned to the various distribution points so that the subsequent sort program can be drawn up.

BACKGROUND OF THE INVENTION

The invention relates to the distribution of mail items whose surfacesare provided with distribution information. The distribution is effectedsuccessively with the aid of various sorting machines, particularlythrough successive sorting operations for the final distribution point.

In the sorting of mail items in sorting machines (e.g. letter-sortingmachines, large-item-sorting machines) a separating station is normallyprovided for each sorting direction. If the number of mail items to besorted exceeds the capacity of the stacker, bin or container at theseparation station, the container is automatically or manually exchangedor emptied.

In certain situations, however, it can be beneficial or even necessaryto flexibly adapt the sorting plan to the number of items to be sortedand the space the items occupy.

If certain sorting directions are especially heavily frequented, it isadvantageous to provide numerous sorting compartments or containers forthese directions, which are emptied in such a way that the sortingcompartments are emptied as infrequently as possible due to the use offullness of capacity indicators (DE 195 28 803 A1).

If a successive sorting is to be performed, a uniform loading of thesorting compartments can reduce the number of necessary sortingcompartments or sorting operations. Because mail items make two or morepasses through machines during successive sorting and the sequence ofthe re-supply of mail items into the machines must be strictly adheredto, it is particularly desirable in terms of mail item handling for themail-item flow from any separation station not to exceed a certainamount of space. In automatic successive sorting machines, thisrequirement is even compulsory because the machine must store the entirevolume of items internally during and between sorting passes; the spaceis therefore apparently limited.

To this point, the operator's experience or quantity statistics of pastdaily mail-item volumes has or have been used in the generation ofsorting plans.

The disadvantage of this procedure is that no dynamic adaptation to themail-item volume that is actually present is effected.

Particularly in successive sorting, solutions have become known in whicha quantity statistic is created (number of mail items per distributionpoint) after the recording of addresses. Based on this statistic thefollowing sorting operations can be optimized with respect to spacerequirements (EP 0 533 536 B1 and U.S. Pat. No. 5,363,971). Based on thequantities of items, the optimization can only be effected impreciselybecause the items have different thicknesses. For a more preciseassessment of the space requirements of the mail items, EP 0 661 106 A2and EP 0 718 049 A2 proposed to detect the item thicknesses with asuitable measuring device and use this information to optimize the latersorting operations.

A more serious disadvantage is that no sorting-plan optimization ispossible in the first machine pass. In automatic successive-sortingmachines, this can make sorting impossible, although a suitablestructuring of the first sorting plan would make sorting possible.

BRIEF SUMMARY OF THE INVENTION

The problem addressed by the invention is to structure the distributionof the mail items in sorting compartments or containers in the sortingto distribution points prior to this sorting such that the items can bedistributed as uniformly as possible to the sorting compartments orcontainers, avoiding overflow situations.

According to the invention, the object is accomplished by themeasurement of the item thicknesses; the determination of thedistribution points; the registration and storage of the thicknesses ofitems associated with the distribution points during the first receptionof items; the calculation of optimized sorting plans for the sortingmachines allocated to the respective distribution points taking intoconsideration data relating to the item thicknesses; and thecorresponding sorting of the items satisfy the prerequisites for thedistribution of the items relating to the object of the invention,knowledge about the present quantities of mail items and itemthicknesses, relating to the distribution points, permits an optimizeddistribution before the first processing of these items in the sortingmachines for the distribution points.

Advantageous embodiments of the invention are herein disclosed.

Hence, according to the prerequisites for control technology in thesorting machines, the optimized sorting plans are transmitted during thefirst reception of the items. In sorting machines associated with thedistribution points, the data relating to the item thicknesses and dataassociated with the distribution points, are transmitted.

It, is advantageous to identify each item by transmitting its thickness,distribution point and an applied ID code.

It, is advantageous to perform the calculation of the optimized sortingplans centrally, and then transmit the sorting plans to the sortingmachines, which saves resources.

In a further advantageous embodiment 5, only the number of mail itemsand the associated, statistically-determined item thicknesses are usedas data relating to the item thickness for each distribution point.

The sorting plans are advantageously optimized such that the items aredistributed to the sorting compartments of the respective sortingmachine as uniformly as possible without the compartments beingoverfilled.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in detail below by way of embodiments.

FIG. 1 illustrates a functional block representation of one embodimentof the present invention wherein an optimized sorting plan is createdduring the first reception of the item and then transmitted.

FIG. 2 illustrates a functional block representation of anotherembodiment of the present invention wherein the optimized sorting plansare created in the sorting machines associated with the distributionpoints.

FIG. 3 illustrates a functional block representation of anotherembodiment of the present invention wherein the optimized sorting plansare created centrally.

DETAILED DESCRIPTION OF THE DRAWING

According to FIG. 1, during the first reception of mail items, the items30 are scanned by optical measuring means 40 during their transport 20in a sorting machine 10 to assess the sorting information located on theitems 30. The item thicknesses are determined with the aid of furthermeasuring means 50.

In the machine control 60, the sorting information for each mail item,such as sorting destination, an identification code (ID code) if needed,and the item thickness, is registered and possible statisticallydetermined. Afterward, in a functional block 110 of the machine control60, the optimized sorting plans for the downstream sorting machine 90associated with the sorting points are calculated. The data relating tothese sorting plans are transmitted to the machine control 100 of therelevant sorting machine 90 via a transmission medium 70. Data networks,transponders or diskettes can serve as a transmission medium 70.

The mail items 30 are transported in containers 80 to the sortingmachine 90 for the respective distribution point.

During sorting in the sorting machines 90 designated for specificsorting destinations, the surfaces of the items 30 are likewise scannedwith optical measuring means 40 for assessing the sorting information(sorting destination) for each item. The sorting is then effected withthe aid of the transmitted, optimized sorting plan.

Corresponding to FIG. 2, in the machine controls 60 of the sortingmachines 10 that receive the items 30 for the first time, after thesorting information (sorting destinations) and the item thicknesses havebeen determined, this information is transmitted via the medium 70, withan identification code and following statistical determination, ifnecessary, to the machine controls 100 of the sorting machines 90designated for the respective distribution points.

There, the optimized sorting plans, according to which the items 30 aresorted after their sorting destinations (distribution points) have beenreceived, are calculated in a corresponding functional block 110.

As can be seen from FIG. 3, in large distribution systems, it can bemore beneficial to transmit the item data (including thicknessinformation) to a central processing unit 110, corresponding to thepreceding examples, for determining the optimized sorting plans, fromwhich point the optimized sorting plans are transmitted to the controls100 of the downstream sorting machines.

The following tables illustrate possible structures of the transmittedor processed statistical data.

Tables 1 and 2 illustrate possible structures of the transmittedstatistical data.

TABLE 1 Sorting Number of Average No. Destination Mail Items ItemThickness 1 78459 120 2.3 2 78476  89 1.9 3 78498 132 3.0

IN Table 1, each sorting destination is identified by a five-digitnumber. Only the number of items and their average thickness (for eachsorting destination) are transmitted.

TABLE 2 Sorting Number of Sequence of No. Destination Mail Items ItemThicknesses 1 78459-123 5 2.3 1.6 1.0 4.1 2.1 2 78459-124 3 1.9 1.1 3.23 78560-100 2 2.1 2.2

In Table 2, each sorting destination is defined by an eight-digitnumber. For each sorting destination, the number of items and thesequence of item thicknesses are transmitted.

In Table 3, the mail items additionally bear or contain anidentification code (ID code), which permits individual items to beunequivocally re-recognized. For each ID code, the destinationinformation is recorded in the form of an eight-digit decimal number;the item thickness is also given.

TABLE 3 ID code Sorting Item No. Destination Thickness 01.01.97-78459-123 2.3 1001 01.01.97- 78959-128 1.9 1003 01.01.97- 78560-100 2.11004

Two examples are presented for optimizing the sorting plans:

EXAMPLE 1

A fine sorting of 10,000 mail items is effected in 250 directionsthrough sorting in a machine having 300 compartments (e.g. an AEGfine-distribution machine). Thus, on average, each compartment is filledwith 40 items. Because each compartment has a loading capacity of about100 items, the machine need not be emptied during the sorting operation.

If it is known before the sorting (through the proposed transmission ofpreviously-collected data) that, for example, 30 of the 250 directionsare especially heavily frequented, with, for example, 160 items each asopposed to the average value of 40, the sorting plan can be modifiedprior to the start of sorting such that additional compartments arereserved for the 30 most heavily frequented directions, for a total of,for example, 250+30=280 of the 300 available compartments. Thecompartments designated for the same sorting directions can be adjacentto one another, so the machine can subsequently be emptied according todirections.

EXAMPLE 2

In successive sorting according to the “Radix sorting method,” mailitems pass through the sorting machine multiple times; in the process,the items are emptied after the first sorting operation and supplied tothe machine again in the proper order for sorting. The “overflow” ofindividual compartments during the first sorting operation is especiallydisadvantageous, because reserve compartments must be resorted also.These compartments must be carefully brought into the proper sequencewith the regular compartments after the later emptying in order to besupplied for the following sorting operation.

If, prior to the first sorting operation, previously-obtainedinformation about item quantities and thicknesses reveals how much spacemust be provided for each sorting direction of the first sortingoperation, the compartments can be allocated in a first sortingoperation such that they are later emptied in the order of theparticular sequence arrangement, and the items can be re-supplied to themachine for the further sorting operations. The same applies for thefollowing sorting operations: When the item quantities and the requiredstack space for each sorting destination are known in advance, thesorting compartments can be allocated such that items for the samesorting destination are deposited into the same compartment, or at leastinto adjacent compartments.

What is claimed is:
 1. A method of distributing a plurality of mailitems whose surfaces are provided with distribution information, themethod comprising the following steps: a) scanning a surface of each ofthe plurality of items, determining a distribution point of each of theplurality of items, and measuring a thickness of each of the pluralityof items, said scanning, determining, and measuring occurring in a firstat least one sorting machine during a first reception of items; b)registering and storing a first set of data comprising item dataassociated with the distribution points of each of the plurality ofitems, said registering and storing occurring during the first receptionof items, and calculating sorting plans for a second at least onesorting machine using a second set of data comprising item data relatingto the thickness of each of the plurality of items, the second at leastone sorting machine designated for distribution points; and c)transporting each of the plurality of items to the second at least onesorting machine; d) sorting each of the plurality of items to individualdistribution points according to said sorting plans.
 2. The methodaccording to claim 1, wherein the step of calculating further includescalculating the sorting plans in controls of said first at least onesorting machine during the first reception of said plurality of items,and said sorting plans are transmitted to controls of the second atleast one sorting machine.
 3. The method according to claim 1, furthercomprising the step of transmitting the second set of data and the firstset of data to the controls of the second at least one sorting machine,the controls of the second at least one sorting machine calculating saidsorting plans.
 4. The method according to claim 3, wherein the step oftransmitting further includes transmitting data relating thedistribution point for each of the plurality of items and an ID code ofeach of the plurality of items said ID code applied upon reception ofthe plurality of items.
 5. The method according to claim 1, furthercomprising the steps of: transmitting the second set of data and thefirst set of data to a central station for calculating the sorting plansfor the second at least one sorting machine, and transmitting thesorting plans to the controls of the second at least one sortingmachine.
 6. The method according to claim 1, wherein the step ofcalculating further includes using a count of each of the plurality ofitems.
 7. The method according to claim 1, further comprising the stepof distributing the plurality of items approximately uniformly tosorting compartments, avoiding overflowing of the compartments.
 8. Anarrangement for distributing a plurality of mail items whose surfacesare provided with distribution information, the arrangement comprising:a first at least one sorting machine for receiving said plurality ofitems; a second at least one sorting machine associated withdistribution points; optical measuring means for assessing sortinginformation located on each of the plurality of items to determine afirst set of data, said first set of data comprising data associatedwith distribution points of the plurality of items; measuring means forascertaining a thickness of each of a plurality of items; said first atleast one sorting machine including means for machine control forregistering and storing a second set of data, said second set of datacomprising data relating to the thickness of each of the plurality ofitems; functional blocks for calculating sorting plans for the second atleast one sorting machine using said second set of data; transmissionmedia for transmitting said first set of data and said second set ofdata to said functional blocks; means for transporting the plurality ofitems from the first at least one sorting machine to the second at leastone sorting machine.
 9. The arrangement according to claim 8, whereinthe means for machine control generates and outputs additional datarelating the thickness of each of the plurality of items.